The Mensa IQ Test: Requirements, Minimum IQ and How to Join

The Mensa IQ test is a supervised admission test used by Mensa, the world's largest and oldest high-IQ society, to identify people who score in the top 2% of the population — the 98th percentile, which means a minimum IQ of about 130–132 on an SD-15 scale. There is no single "Mensa test" worldwide: each national group administers its own proctored admission test and also accepts prior evidence from a list of approved intelligence tests. What never changes is the bar — two standard deviations above the mean, a level reached by roughly 1 person in 50.

One thing to be clear about up front: IQ Revealed is not affiliated with Mensa, and our online assessment is not a Mensa admission test. It's a practice-style self-assessment using the same matrix-reasoning format many admission tests rely on — useful for seeing roughly where you stand before committing to a supervised session.

Mensa requirements at a glance

There are only two Mensa membership requirements, and one of them is a test score:

• A qualifying score. At or above the 98th percentile on an approved, supervised intelligence test. That means a minimum IQ of roughly 130–132 on an SD-15 scale such as the WAIS, or 148 on the SD-24 Cattell scale. The score can come from Mensa's own admission test or from prior evidence.
• Dues. Each national Mensa sets its own annual membership fee, plus a separate fee for testing or for evaluating a prior score. Fees change, so check your national group for current figures rather than trusting any number you read elsewhere.

That is the whole list. There is no education, occupation or nationality requirement — the score is the only criterion, which was Mensa's founding premise in 1946.

What Mensa actually is

Mensa was founded in Oxford, England in 1946 by barrister Roland Berrill and scientist-lawyer Lancelot Ware, with a simple premise: a society open to anyone whose IQ places them in the top 2%, regardless of background, politics or profession. Today Mensa International has national chapters in dozens of countries and well over 100,000 members worldwide. It is a social organization — local meetups, special interest groups on everything from chess to beekeeping, annual gatherings, and member publications. Membership is not a qualification or credential; it's a club whose only entry requirement is a test score.

The minimum IQ for Mensa: the 98th percentile on an accepted test

Mensa's admission standard is a percentile, not a fixed number: you must score at or above the 98th percentile on an approved, supervised intelligence test. That is why the minimum IQ Mensa requires is a different number on different tests, which confuses a lot of applicants.

Why the gap between 132 and 148? Both describe the same rarity. IQ scores are positions on a bell curve, and the standard deviation sets how spread out the numbers are. On an SD-15 scale like the WAIS, the 98th percentile sits about two standard deviations above the mean of 100 — roughly 130–132. The Cattell scale stretches the same curve with an SD of 24, so two standard deviations lands at 148. A Cattell 148 and a WAIS 132 are the same relative performance. This is why comparing raw numbers across tests is meaningless without knowing the scale — our guides to IQ percentiles and the IQ scale walk through the math, or use the IQ percentile calculator to compare equivalent scores directly.

The Mensa admission test (or entrance exam): what to expect

If you don't have a prior qualifying score, the standard route is a proctored admission test session organized by your national Mensa chapter. Formats vary by country, but a typical session (American Mensa's, for example) involves a battery of timed sections covering pattern recognition, logical reasoning, verbal and numerical problems, completed in roughly an hour under supervision. Some national groups use culture-fair, non-verbal tests built around matrix puzzles — abstract grids where you infer the rule and pick the missing piece, the same format described in our guide to how IQ tests work.

You register through your national chapter, pay a modest testing fee, and take the test at a scheduled venue with a proctor. Results arrive by mail or email a few weeks later. Note that scores from Mensa's own admission test are typically reported as pass/fail against the 98th-percentile bar rather than as a precise IQ number.

Online Mensa tests: practice, not admission

Mensa's websites offer online tests — the international Mensa Workout and various national online practice tests, some free and some paid. These are explicitly practice and entertainment tools: no online, unsupervised test can qualify you for membership, because there's no way to verify who took it or under what conditions. The same logic applies to every online IQ test, ours included. A well-built online assessment can give you a realistic estimate of where you'd land and excellent familiarity with the question formats — but the score that gets you into Mensa must come from a supervised session or an approved psychologist-administered test.

The prior-evidence route: joining with a score you already have

Already been tested? Most national Mensa groups accept documented scores from approved tests — commonly the WAIS, Stanford-Binet, and certain school- or military-administered cognitive tests — provided the test was administered and certified by a qualified professional, such as a licensed psychologist. You submit the official report, pay an evaluation fee, and if the score meets the 98th-percentile bar for that instrument, you're in without sitting Mensa's own test. Each national chapter publishes its list of accepted tests and qualifying scores; check yours before booking anything.

How to join Mensa: the four steps

1. Find your national group and read its list. Every chapter publishes which tests it accepts and the qualifying score for each. Requirements differ by country, so this is the step that saves the most wasted money.
2. Pick your route. Either sit the supervised admission test your chapter runs, or submit prior evidence — an approved test administered by a qualified professional.
3. Register and pay the fee. A testing fee for the admission session, or an evaluation fee for reviewing prior evidence.
4. Get your result and join. Results normally arrive within a few weeks, reported as qualified or not qualified against the 98th-percentile bar. If you qualified, paying annual dues activates membership.

What is the average IQ of a Mensa member?

Mensa publishes no statistics on its members' scores, so any figure you see is an estimate. But the arithmetic gives a defensible one. If membership is drawn from everyone above the 98th percentile, members are a slice of the top tail of the distribution rather than a group clustered at the cutoff — and the average of that slice sits above the entry bar, not on it.

For a normal distribution with a mean of 100 and a standard deviation of 15, the average score among everyone above the 98th percentile is about 136 — roughly five points above the ~131 entry threshold, and about 36 points above the population average of 100. On the SD-24 Cattell scale the same relative standing works out to about 158.

The average is the least interesting number here, though, because the distribution is lopsided. Scores get rarer as they rise, so most qualifiers cluster just above the bar rather than spreading evenly above it:

So the median qualifier is around 135 while the mean is around 136, and roughly half of everyone eligible sits within about four points of the entry threshold. Two honest caveats: all of this assumes members are a random sample of everyone eligible, when in practice people who test repeatedly or who are unusually motivated to join are over-represented; and it describes the pool, not any individual member.

How to prepare

You can't study your way to a genuinely higher IQ in a few weeks — the evidence on that is covered honestly in how to increase your IQ. What you can do is remove everything that artificially lowers your score on test day:

• Get familiar with matrix puzzles. First-time takers lose points to unfamiliarity, not ability. Working through practice-style tests teaches you the common rule types — rotation, progression, addition/subtraction of elements — so you spend test time reasoning, not decoding instructions.
• Practice under time pressure. Admission tests are strictly timed. Train yourself to move on from a stuck question and bank the easier points.
• Sleep and schedule. Sleep deprivation measurably impairs working memory and attention. Book a morning slot if you're a morning person, sleep properly for several nights before, and skip the extra coffee that makes you jittery.
• Take a realistic practice run. A timed, matrix-based online assessment tells you approximately where you stand relative to the 98th-percentile bar before you pay for a proctored session.

Mensa membership: what you get, and whether it is worth it

That depends on what you want from it. Members get local and national events, hundreds of special interest groups, journals and newsletters, and a ready-made social circle that enjoys puzzles and argument in equal measure. What membership does not do is certify anything professionally — employers don't hire on Mensa cards, and a 98th-percentile score says nothing about the extreme claims you see in lists of the highest IQs ever recorded. For many members the honest answer is simpler: they took the test out of curiosity, passed, and stayed for the people.

The bottom line

Qualifying for Mensa means one thing: a supervised, approved test score at or above the 98th percentile — about 130–132 on an SD-15 scale, 148 on the SD-24 Cattell scale. Online tests, whether Mensa's own workout or a self-assessment like ours, are practice instruments that estimate your standing and build familiarity. If a realistic practice run puts you comfortably in the top few percent, booking a proctored session is a reasonable next step.